1. Field of the Invention
The present invention relates to a tape recorder, and more particularly, to a power supply device that supplies power for a tape recorder to a tape-end detecting sensor capable of detecting the passing of a magnetic portion of a magnetic tape.
2. Description of the Related Art
A tape recorder having a deck mechanism, such as a video tape recorder (VTR), a digital audio tape (DAT), and a camcorder, is an apparatus that records and reproduces audio and video information from a magnetic tape running along a predetermined path.
FIG. 1 shows an example of the interior of a camcorder employing a moving deck 100. As shown in FIG. 1, the moving deck 100 of the recorder includes a main-chassis 110 and a sub-chassis 120 mounted on the main-chassis 110. The sub-chassis 120 reciprocally slides on the main-chassis 110 when a magnetic tape is loaded and unloaded.
A head drum 130, a capstan driving unit 160, and a loading motor 140 are disposed on the main-chassis 110. A magnetic tape running guiding device 150 is disposed on the sub-chassis 120. The magnetic tape running guiding device 150 includes a plurality of pole members 152 and a plurality of rollers 151, a pair of reel tables 170 on which a tape reel of the tape cassette (not shown) is seated with a tape cassette being loaded, and an idler assembly 180 for controlling a rotation driving force to be transmitted to the reel table 170. Also, the tape recorder includes a tape-end detecting sensor disposed at an upper portion of the sub-chassis 120, for detecting the passage of a leading portion of a magnetic tape, for example a transparent portion of the tape, after a magnetic portion of the magnetic tape passes the sensor.
The tape-end detecting sensor employs a light detecting method using a light-emitting element 190 such as an LED, and a light-receiving element (not shown). As shown in FIG. 1, the light-emitting element 190 is seated on a seating portion 191A of a reel cover 191 so that it is supported by an upper portion of the sub-chassis 120, and the light-receiving element is fixedly disposed at both inner walls of the deck 100. Also, the positions of the light-emitting element 190 and the light-receiving element may be switched according to the type of tape recorder in which they are employed. Also, there are various configurations of the sensor. For example, a detecting sensor including the light-emitting element 190 and the light-receiving element can be formed integrally with each other and seated on the reel cover 191.
The tape recorder further includes a power supply device for supplying power to the light-emitting element 190 disposed at the upper portion of the sub-chassis 120, or to the light-receiving element from a power source device (not shown) provided in the deck 100. The power supply device includes the reel cover 191, a first power transmitting member 193, a second power transmitting member 197, and a resilient pressing member 195.
The reel cover 191 is disposed on the sub-chassis 120 to cover the reel table 170 and the idler assembly 180, and is made of a metallic plate or formed by injection-molding of a synthetic resin material. In accordance with the trend toward a compact-sized tape recorder, the reel cover 191 has a complicated shape in order for the reel cover 191 to perform various functions in a narrow space of the deck 100. Accordingly, the reel cover 191 is preferably a plate made of synthetic resin material, because such a reel cover 191 can be shaped as desired with less restrictions than the metallic plate type. The first power transmitting member 193 is electrically connected to the light-emitting element 190 to be seated on the seating portion 191A of the reel cover 191, and has one end fixed to a lower surface of the reel cover 191. Generally, the first power transmitting member 193 uses a flexible printed circuit (FPC). The second power transmitting member 197 is disposed on an upper surface of the sub-chassis 120 and is electrically connected to the power supply device. At an end of the second power transmitting member 197 is disposed a second contacting portion 197A that comes into contact with a first contacting portion 193A of the first power transmitting member 193 when the reel cover 191 is mounted on the sub-chassis 120. The second power transmitting member 197 generally uses the FPC as the first power transmitting member 193.
After a long period of use, or during manufacture of the conventional power supply device of the tape-end detecting sensor employing the reel cover 191 made of synthetic resin, it is often the case that the reel cover 191 becomes inelastically deformed which causes the first contacting portion 193A to be separated from the second contacting portion 197A fixed to the one end of the second power transmitting member 197 on the sub-chassis 120. According to conventional methods to solve this problem, the reel cover 191 is instead made of metallic material, or an extra resilient pressing member 195 is required to resiliently press the first contacting portion 193A downward from the reel cover 191. When the resilient pressing member 195 is used, the reel cover 191 is mounted on the sub-chassis 120 in a manner as shown in FIG. 2.
However, the conventional tape recorder having the above-described construction has drawbacks such as increased manufacturing cost and an increased number of manufacturing processes due to the presence of the extra resilient pressing member 195.